Floods happen world wide, which does not mean that there was a single world drowning deluge. There is plenty of evidence for the former, nothing for the latter. Plus after the ice age, the most probable source of flood stories, people were living in small family units or tribes, hence if a group of people saved themselves from a local flood event, it was a family unit.
When's the last time you heard of a continent wide flood? That is what is necessary to form some of the mountains. The world wide flood solves that problem.
You may need to attend a Geology class, just a friendly suggestion.
